This is the complement of (445) - If Preempt_Mode is False, or if the Priority ... is greater than or equal to the local priority, and so should be Preempt_Mode is True and the Priority is less than the local priority

(630) ++ MUST send ND Router Advertisements for the virtual
router.
(635) ++ If Accept_Mode is False: MUST NOT drop IPv6 Neighbor
Solicitations and Neighbor Advertisements.
(640) +-endif // ipv4?
and
(705) -+ If the Priority in the ADVERTISEMENT is zero, then:
(710) -* Send an ADVERTISEMENT
(715) -* Reset the Adver_Timer to Advertisement_Interval
(720) -+ else // priority was non-zero
(725) -* If the Priority in the ADVERTISEMENT is greater
than the local Priority,
(730) -* or
(735) -* If the Priority in the ADVERTISEMENT is equal to
the local Priority and the primary IPvX Address of the
sender is greater than the local primary IPvX Address, then:
(740) -@ Cancel Adver_Timer
(745) -@ Set Master_Adver_Interval to Adver Interval
contained in the ADVERTISEMENT
(750) -@ Recompute the Skew_Time

It should say:

(630) + MUST send ND Router Advertisements for the virtual
router.
(635) + If Accept_Mode is False: MUST NOT drop IPv6 Neighbor
Solicitations and Neighbor Advertisements.
(640) -endif // ipv4?
and
(705) + If the Priority in the ADVERTISEMENT is zero, then:
(710) * Send an ADVERTISEMENT
(715) * Reset the Adver_Timer to Advertisement_Interval
(720) + else // priority was non-zero
(725) * If the Priority in the ADVERTISEMENT is greater
than the local Priority,
(730) * or
(735) * If the Priority in the ADVERTISEMENT is equal to
the local Priority and the primary IPvX Address of the
sender is greater than the local primary IPvX Address, then:
(740) @ Cancel Adver_Timer
(745) @ Set Master_Adver_Interval to Adver Interval
contained in the ADVERTISEMENT
(750) @ Recompute the Skew_Time

Notes:

Between
(750) -@ Recompute the Skew_Time
and
(755) @ Recompute the Master_Down_Interval

the indentation level marking changes from '-@' to '@'. The corrected text removes the extra '+' from (630) to (640) and '-' from (705) to (750).